Document EP 1 768 234 A1 describes an electric machine of the above-described type, wherein it is specifically a motor and a completely enclosed and fan-cooled embodiment. In this known embodiment, the inner cooling fan impeller is disposed on the side of the stator and of the rotor facing towards the outer cooling fan impeller, so that the two cooling fan impellers are separated from each other by the one first end wall of the housing.
The document EP 0 387 743 B1 or the corresponding publication DE 690 04 834 T2 also describes a very similar instance of prior art, namely a closed, air-cooled electric motor. In this case, however, the inner cooling fan impeller is disposed on the other side of the rotor and of the stator, which other side lies at a distance from the outer cooling fan impeller.
The object of the present invention is to further improve the cooling and at the same time in particular the heat dissipation from the interior of the housing to the outside.
This is inventively achieved by the features described herein.